Capillaster gracilicirrus Clark AH, 1912

Es, Mekhova & Ta, Britayev, 2015, Soft substratecrinoids (Crinoidea: Comatulida) andtheir macrosymbionts in Halong Bay (North Vietnam), Raffles Bulletin of Zoology 63, pp. 438-445 : 441

Capillaster gracilicirrus Clark AH, 1912

( Fig. 2b )

Capillaster gracilicirra Clark AH, 1912: p. 18 ; Clark AH, 1918: pp. 10 (in key), 11, 276, pl. 11, fig. 3; Messing, 2015.

Material. South China Sea, Halong Bay , Katba Is., St. 8, 5 m depth, 6 May 2012 – 1 specimen .

Coloration. Dark brown pinnules and light brown arms, becoming fully dark brown in alcohol.

Measurement. Thirty eight arms, with length unknown (damaged); 22 cirri 19 mm in length.

Taxonomic remarks. Morphology of this specimen is in accordance with the diagnoses of C. gracilicirrus provided by Messing (2015).

Ecological notes. Very rare. Solitary, 5 m depth, on muddy sand close to the base of zoantarian. Probably nocturnal, during the day, fully exposed but with arms folded. Habitat of С. gracilicirrus was previously unknown.

Symbionts. Polychaete Hololepidella cf. laingensis . Distribution. Halong Bay, northern Vietnam; Madura Island, Indonesia ( Messing, 2015). First record from the coast of Vietnam.

Figures

Fig. 2. Proximal ray articulations, branching patterns and arrangement of cirri: a, Comatula purpurea; b, Capillaster gracilicirrus; c, Amphimetra tessellata. IIBr and IIIBr division series. Scale bar = 1 cm.